1. Field of the Invention
The invention relates to an apparatus for forming a succession of mutually overlapping products, and particularly folded printed products, and the invention particularly relates to such an apparatus which comprises at least one chain, which is equipped with grippers for gripping individual products, and which chain is guided next to a vane wheel of a folding apparatus for automatically guiding the products to be overlapped out of the vane wheel and for passing the products to a transfer station in an overlapping arrangement.
2. Description of the Prior Art
To enable further mechanical processing of printed products, and particularly thin printed products, they often should be arranged in a mutually overlapping arrangement. Other items may also have to be placed in a mutually overlapping formation. For proper overlapping, the overlap spacing must have a distribution range that does not exceed a certain maximum.
Printed products are delivered to a transport for being overlapped by a vane wheel, comprised of one or a plurality of coaxial, same size, axially spaced discs, each having a respective plurality of vanes or fingers projecting from the surface of the disc and partially wrapped about and spaced away from the surface of the disc. Strippers remove each product from the vane wheel in its turn and deposit it on a transport in an overlapping manner with respect to the next preceding product.
To provide overlapped, folded printed products, overlap spacing of the required accuracy cannot be realized with strippers which are conventionally provided for cooperation with a vane wheel. This is because the folded products rebound at too high a speed from the stripper units. Consequently, the folded products accumulate between the vanes of the vane wheel and the stripper units and lose contact with the vanes. Furthermore, during the further delivery process, the products no longer follow the stripper units with the required accuracy of timing. This produces differences in the overlap spacing that exceed a permissible amount.
A relatively insignificant improvement in delivery can be achieved through optimal shaping of the vane. Further, it is possible to reduce the speed of rebound of the printed products or items on the stripper units by increasing the number of vanes on the vane wheel. However, these expedients do not ensure the required delivery tolerances for operation at the high operating speeds which are usual today.
U.S. Pat. No. 3,390,508 discloses apparatus for automatically guiding the printed products or other items out of the vane wheel by means of a chain which is equipped with grippers. In principle, accurate overlap spacing is attainable using this apparatus. But, this apparatus is not concerned with forming a succession of mutually overlapping printed items. Further, in this apparatus, because the chain is guided concentrically, and not eccentrically, about the axis of rotation of the vane wheel, the chain spacing or the gripper spacing must be selected in accordance with the vane spacing at the bases of the vanes on the peripheral surface of the vane wheel. If it were desired to use this apparatus to place a succession of mutually overlapping printed items on a receiving means or transport belt, it would be impossible to bring the product overlap spacing to the required, relatively small dimension.